Detailed oceanic structure in the vicinity of the shoal Kokusho-sone

The detailed oceanic structure was observed near the shoal Kokusho-sone (3000N, 12830E), which is located near the axis of the Kuroshio in the East China Sea. The detailed temperature cross-sections along the meridian 12830E, which passes over the shoal, strongly suggest that upwelling is forced along the north slope of the shoal. The behavior of the coastal waters near the Kuroshio front and of the cold water belt along the north-western side of the Kuroshio are also discussed.     

Petrology of Aoso volcano,northeast Japan arc: temporal variation of the magma feeding system and nature of low-K amphibole andesite in the Aoso-Osore volcanic zone

The Aoso volcano is a member of the newly defined volcanic front of Northeast Japan, characterized by the occurrence of low-K and hornblende andesites. Its activity can be divided into three stages: the early, caldera-forming, and late stages. While petrographic and geochemical data show all products underwent magma mixing or co-mingling, Sr and Nd isotopic ratios indicate that all are consanguineous. The end-member magmas are basaltic and andesitic in the early stage, but basaltic and dacitic in the late stage. In the caldera-forming stage, hornblende-free and hornblende-rich andesites co-mingled, which triggered an explosive eruption leading to caldera formation. Hornblende occurs also in the dacite from the early part of the late stage. These hornblende andesites and dacites are lower in magmatic temperature compared to hornblende-free andesites. The estimated basaltic end-member is low-K and high in magmatic temperature, and can be derived by a high degree of partial melting of mantle under the volcanic front. The estimated andesitic and dacitic end-members cannot be derived from the basaltic end-member magma through fractional crystallization, but can be derived from partial re-melting of the solidified low-K basalt, leaving amphibolitic and gabbroic residues, respectively.     

Dynamical downscaling: Fundamental issues from an NWP point of view and recommendations

Dynamical downscaling has been recognized as a useful tool not only for the climate community, but also for associated application communities such as the environmental and hydrological societies. Although climate projection data are available in lower-resolution general circulation models (GCMs), higher-resolution climate projections using regional climate models (RCMs) have been obtained over various regions of the globe. Various model outputs from RCMs with a high resolution of even as high as a few km have become available with heavy weight on applications. However, from a scientific point of view in numerical atmospheric modeling, it is not clear how to objectively judge the degree of added value in the RCM output against the corresponding GCM results. A key factor responsible for skepticism is based on the fundamental limitations in the nesting approach between GCMs and RCMs. In this article, we review the current status of the dynamical downscaling for climate prediction, focusing on basic assumptions that are scrutinized from a numerical weather prediction (NWP) point of view. Uncertainties in downscaling due to the inconsistencies in the physics packages between GCMs and RCMs were revealed. Recommendations on how to tackle the ultimate goal of dynamical downscaling were also described.     

辽东地区沉积变质硼矿床及硼同位素研究

辽东地区元古界硼矿床属于沉积变质硼矿。根据现代盐湖沉积 ,认为硼矿物沉积通常为硼砂 ,然后在区域变质作用过程中 ,硼砂矿物转变为硼镁矿物或硼铁矿等硼酸盐矿物 ,但辽东硼矿床中不同硼矿物的硼同位素有一定差别。电气石富10 B ,δ11B值较低或呈负值 ;而硼镁石与硼镁铁矿类矿物明显富集11B ,δ11B值较高 ,为 +2 3‰～ +17 4‰。根据水岩作用过程中硼同位素分馏特征的研究 ,11B与10 B比较有下列 4个特征 :( 1) 11B属于极不相容元素 ,优先进入水相 ,因此在变质残余矿物相中形成低的δ11B值 ;( 2 )在蚀变和交代变质反应中硅优先替代11B进入矿物晶格 ,因此在硅化交代中可以降低δ11B值 ,而脱硅反应中可以提高δ11B值 ;水化作用中 ,OH-带入11B ,使富水矿物具有较高的δ11B值 ;( 3)热水沉积及热液交代成因电气石均具有较低的δ11B值或者为负值 ;( 4)通过最近的研究表明 ,在热蒸馏过程中 ,硼同位素会发生明显的分馏 ,11B倾向于进入蒸汽相 ,而使残余相或后蒸馏相亏损11B ,形成较低的δ11B值。因此可以认为辽东地区元古界硼矿床属于热水沉积电气石岩在后期区域变质或热变质过程中分解出硼酸气水溶液交代镁碳酸盐形成硼镁石或硼镁铁矿矿物 ,而非蒸发沉积变质矿床。